Patent GB-522128-A (GB)
Abstract: 522,128. Printing; vat dye derivatives. SOC. OF CHEMICAL INDUSTRY IN BASLE. Dec. 6, 1938, Nos. 35516, 35517 and 35518. Convention dates, Dec. 7, 1937, July 12, 1938 and Nov. 11, 1938. [Classes 2 (iii) and 15 (ii)] Vat dyestuff prints (including discharge prints) are produced on textile products, e.g. fibres containing cellulose, such as cotton or artificial silk, or animal fibres, such as wool or silk, by using the vat dyestuff in the form of a quinhydrone-like compound, which may be prepared by the process described in Specification 522,127. The quinhydrone-like compound may advantageously be first treated with an acid, e.g. a mineral acid such as hydrochloric or sulphuric acid, which may be wholly or in part replaced by acids the salts of which have hydrotropic properties. If desired the quinhydrone-like compound may be produced in the printing paste, e.g. by partial reduction of the vat dyestuff. There may be added to the printing pastes hydrotropic agents, reduction catalysts, fluxing agents, diluents, bactericides, alkali compounds, heavy metal salts and dust preventing agents. Instead of the quinhydronelike compounds themselves there may be employed the products obtained therefrom by the action of an oxidizing agent, e.g. air, preferably in an aqueous medium. Suitable starting materials, are indigoid vat dyestuffs, e.g. of the bis-indol-indigoid, indol-thionaphthene - indigoid, bis - thionaphthene - indigoid and naphthalene - indol - indigoid series, particularly those containing at least one substituent, and anthraquinonoid vat dyestuffs, particularly those containing as substituents halogen atoms, methoxy, amino or substituted amino groups and/or fused-on rings, e.g. carbazole or other 5-membered rings or acridone or other heterocyclic rings. In examples : (1) the product of Example (8) of Specification 522,127 is ground with water, glycerol and a mixture of sodium o- and ptoluenesulphonate and then mixed with a potash thickening made by boiling together wheat starch, tragacanth, British gum, potash, glycerine and water, then sodium formaldehyde sulphoxylate is added and the paste is printed on cotton; (2) the isobutyric acid product of Example (12) of Specification 522,127 is stirred with water, glycerol, and a mixture of sodium 1 - methyl - 4 - isopropylbenzene - 2 - and 3-sulphonates (or other hydrotropic agents, with or without further printing assistants, e.g. a protective colloid, a fluxing agent or a bactericide), and the mixture is employed as in (1); for the preparation of the starting material the isobutyric acid may be replaced by other acids, e.g. sulphuric, hydrochloric or phosphoric acid, or an acid the salts of which are hydrotropic, e.g. benzene-, toluene- or naphthalenesulphonic acids, phthalic acid' monoesters of alcohols, cymenesulphonic acids, pdiethylaminobenzoic acid or anthraquinonesulphonic acids ; (3) the isobutyric acid product as in (2) is mixed with sodium 1-methyl-4- isopropylbenzene-2- and 3-sulphonates, then with sodium formaldehyde sulphoxylate and a potash thickening as in (1), and the paste is printed on cotton; (4) the first product of Example (11) of Specification 522,12 is ground with water, glycerol, sodium N-benzylaniline- 4-sulphonate and crude cresol, and the mixture is employed as in (1); (5) in the process of (1), the initial paste is stirred until oxidized before being mixed with the thickener; (6) the isobutyric acid product used in (2) is made into a paste with water, glycerol and a mixture of sodium o- and p-toluenesulphonates, and the mixture is employed as in (1) ; (7) 6:6<SP>1</SP>- diethoxythioindigo is mixed with glycerol, sodium benzenesulphonate and caustic soda lye and partially reduced with sodium hydrosulphite, the product is neutralized with formic acid (or other acid, e.g., sulphuric, hydrochloric, phosphoric, benzene-, toluene- or naphthalenesulphonic acids, a phthalic acid monoester of an alcohol, cymenesulphonic acids, p-dimethylaminobenzoic acid or N- benzylaniline-4-sulphonic acid), and the resulting mixture is employed as in (6); the sodium benzenesulphonate and glycerol may be replaced wholly or in part by other hydrotropic bodies, protective colloids, fluxing agents or bactericides ; (8) 2:1:2:1<SP>11</SP>-naphththioindigo is ground with sodium o- and p-toluenesulphonates, caustic soda, glycerol, sodium hydrosulphite and water, and the product is mixed with sodium formaldehyde sulphoxylate and a potash thickening as in (1) and printed as in (6); (9) in the process of (8), the potash thickening is incorporated in the initial mixture instead of being added subsequently ; (10) Ciba Yellow G is ground with water, glycerol, caustic soda, sodium 1-methyl-4-isopropylbenzene-2- and 3-sulphonates and cresol, and partially reduced with sodium hydrosulphite, and the mixture is employed as in (1); (11) dimethoxydibenzanthrone is ground with glycerol, then mixed with sodium cymenesulphonate, caustic soda lye and sodium hydrosulphite, and the mixture is employed as in (1) ; (12) the product of Example (4) of Specification 522,127 is treated with hydrochloric acid, ground with water, glycerol, sodium benzenesulphonate and waste sulphite liquor, and the product is employed as in (1).